Ubuntu 18.04.05 LTS AMD64 was what I was trying to install.
ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.15
ProcVersionSignature: Ubuntu 5.4.0-42.46~18.04.1-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.16
Architecture: amd64
CasperVersion: 1.394.3
CurrentDesktop: ubuntu:GNOME
Date: Thu Jun 17 16:39:34 2021
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd quiet splash --- maybe-ubiquity
LiveMediaBuild: Ubuntu 18.04.5 LTS "Bionic Beaver" - Release amd64 (20200806.1)
ProcEnviron:
LANGUAGE=en_US.UTF-8
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=en_US.UTF-8
LC_NUMERIC=C.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)
The following errors can be found in UbiquitySyslog.txt which was automatically attached to this bug report:
Jun 17 20:39:10 ubuntu kernel: [ 451.945435] SQUASHFS error: zlib decompression failed, data probably corrupt
Jun 17 20:39:10 ubuntu kernel: [ 451.945444] SQUASHFS error: squashfs_read_data failed to read block 0x492caa65
It's possible you have a bad write to your media. If you're still having problems please try the option to check the integrity of the image from the installer boot menu, and if this confirms that the media is corrupt, try re-writing and/or re-downloading it.